<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>

	<link rel="stylesheet" type="text/css" href="../../themes/default/easyui.css">
	<link rel="stylesheet" type="text/css" href="../../themes/icon.css">
	<link rel="stylesheet" type="text/css" href="../demo.css">
	<script type="text/javascript" src="../../jquery.min.js"></script>
	<script type="text/javascript" src="../../jquery.easyui.min.js"></script>

	
	<style>
	.a1{
		background-color:red;
	}
	.a2{
		background-color:blue;
	}
	.a3{
		background-color:pink !important;
	}
    </style>
</head>


<body>


</body>
<script>

let s1 = Symbol.for('foo');
let s2 = Symbol.for('foo');
let s3  = Symbol('foo')

console.log(s1 === s2) // true
console.log(s1 === s3)


</script>
</html>